基于ABAQUS有限元数值分析的软弱煤岩体巷道锚杆孔底扩孔力学特征研究

Research on mechanical characteristics of bolt-hole reaming in soft coal-rock mass based on ABAQUS finite element analysis

针对松软煤岩体巷道锚杆支护时出现锚固力低、锚固力衰减速度快等问题,基于ABAQUS有限元数值模拟软件,模拟分析了软煤和砂质泥岩两种情况下锚杆孔底扩孔后的孔壁围岩力学特征。结果表明:在相同围压作用下,扩孔段直径与围岩的强度呈负相关关系;相同岩性条件下,扩孔段最大直径与围压大小也呈负相关关系;验证了在煤及砂质泥岩中能达到较好的扩孔效果。在井下现场采用研制的单翼扩孔装置,分别在软煤和砂质泥岩条件下进行扩孔锚固试验,软煤和砂质泥岩扩孔锚固力显著大于不扩孔状态的锚固力。

In view of the problems of low anchorage torce and fast for decay rate in the bolting of loose coal- rock mass roadway, the finite element numerical simulation software ABAQUS was used to simulate and analyze wall rock mechanical characteristics of the bolt-holes reaming in the sandy mudstone and soft coal seam. The results showed that under the same confining pressure, the diameter of the reaming section was negatively cor- related with the strength of the surrounding rock. Under the same lithologic condition, the maximum diameter of the reaming section was negatively correlated with the confining pressure, which verified the characteristics of coal seam and sandy mudstone can meet better reaming ettect. The reaming and anchoring tests were carried out in soft coal seam and sandy mudstone with a single-wing reaming device that developed in situ. The anchor- age force of bolt-hole reaming in soft coal seam and sandy mudstone was significantly larger than that of bolt- hole non-reaming.